Territory



(No Model.)

B. B. KARN.

ROLLER TENSION FOR SELF BINDERS, 688.

Fig.1

ATTORNEY UNITED STATES PATENT OFFICE.

EDIVIN B. KARN, OF BRITTON, DAKOTA TERRITORY.

ROLLER-TENSION FOR SELF-BINDERS, 84,0.

SPECIFICATION forming part of Letters Patent No. 395,059, dated December25, 1888.

Application filed April 25, 1888. Serial No. 271,864 (No model.)

To all whom it may concern.-

Be it known that I, EDWIN B. KARN, a citizen of the United States,residing in Britton, in the county of Marshall and Territory of Dakota,have invented certain new and useful Improvements in Roller-'lensionsfor Self- Binders, &c., of which the following is a specification.

My invention is in the nature of a tension device designed for the twineof self-binding harvesters, but applicable also to general use; and itconsists in the peculiar construction and arrangement of devicesoperating under a rolling friction, as will be hereinafter fullydescribed, and pointed out in the claim.

Figure l is a front view, and Fig. 2is side elevation, of the device;and Fig. 3 is a crosssection through the axis of one of the rollers online so so of Fig. 2.

A is any suitable frame.

B B are two rollers arranged to bea" against each other. Both theserollers are arranged exactly alike. Each has its journals in movableboxes (1, which slide longitudinally in the slots of the frame A.Against these boxes there bears at each end of the roller rods C", whichare forced by spiral springs b inwardly, so as to cause the roller to bespring-seated or yielding. The rods 0 pass through end bars of the frameA, and are screw-threaded and provided with nuts 0. Against these nutsone end of the springs b bear, while the other end of the spring bearsagainst the end bar of the frame. By turning these nuts 0 it will beseen that the springs are put under more or less tension, and thepressure which the roller exerts is thus regulated. On the rods,

just inside the nuts 6, are other nuts, 0', and around the rods, justinside these, are disposed spiral springs (I, which at their inner endsbear against a brake-bar, D, which bears with a sliding frictionalcontact against the surface of the roller. These brake-bars supply aretardation for the cord as it passes between the rollers by retardingthe rollers, and this serves to tighten the cord to suit therequirements of the knotting devices. This retardation of the rollersmay be varied by varying the tension of the spiral springs d by screwingthe nut-s 0' up or down on the rods.

WVith this form of tension device for the cord the tension is not liableto break the cord or twine if lumpy or weak in places, as is likely tooccur when it passes over or through stationary holders.

I do not confine my invention to use on self-binding harvesters; but mayuse it generally in the arts as a tension device for a passing cord orthread.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

The tension device consisting of the frame A, the rollers B B, havingtheir journals in boxes sliding in guides in the frame, the screwrods(7, with springs 1), nuts 0, springs d, nuts 0', and brake-bar D,sliding in the guide and bearing upon the circumference of the roller,substantially as and for the purpose described.

EDWIN B. KARN.

\Vitnesses:

T. B. MCDONOUGH, WILLIAM KOSTENBORDER.

